1. Field of the Invention
This invention applies to transporters concerned with guidance and propulsion of heavy loads from place to place about the floor. In this industry, load levitates upon a pressurized plenum cushion of air during movement. An unrelated industry uses a tractor that includes a similar piston weight lifting structure to that of this invention, but is used for a different purpose. The purpose of the tractor lifting device in that industry is to lift the front end of a mobile home trailer, fifth wheel tailer, or boat trailer up off their rest frame for wheeling about by tractor. This industry is different from the industry of my invention for the primary reason that the loads to be moved are not fluid plenum levitated, but instead are supported by a trailer with wheels. An example of an invention in this other industry includes that disclosed in U.S. Pat No. 3,995,876 by Ronne, Dec. 7, 1976.